diff mbox

[2.6.36-rc3,1/1] IPv6 BUG: Temp addresses are immediately deleted after being created.

Message ID 20100922160427.GB11185@external.electric.ath.cx
State Not Applicable, archived
Delegated to: David Miller
Headers show

Commit Message

Glenn Wurster Sept. 22, 2010, 4:04 p.m. UTC
There is a bug in the interaction between ipv6_create_tempaddr and 
addrconf_verify.  Because ipv6_create_tempaddr uses the cstamp and tstamp 
from the public address in creating a private address, if we have not 
received a router advertisement in a while, tstamp + temp_valid_lft might be 
< now.  If this happens, the new address is created inside 
ipv6_create_tempaddr, then the loop within addrconf_verify starts again and 
the address is immediately deleted.  We are left with no temporary addresses 
on the interface, and no more will be created until the public IP address is 
updated.  To avoid this, set the expiry time to be the minimum of the time 
left on the public address or the config option PLUS the current age of the 
public interface.

Sending again because of a previous e-mail header issue.

Signed-off-by: Glenn Wurster <gwurster@scs.carleton.ca>
---
 net/ipv6/addrconf.c |    7 ++++---
 1 files changed, 4 insertions(+), 3 deletions(-)

 	int ret = 0;
@@ -886,12 +886,13 @@ retry:
 		goto out;
 	}
 	memcpy(&addr.s6_addr[8], idev->rndid, 8);
+	age = (jiffies - ifp->tstamp) / HZ;
 	tmp_valid_lft = min_t(__u32,
 			      ifp->valid_lft,
-			      idev->cnf.temp_valid_lft);
+			      idev->cnf.temp_valid_lft + age);
 	tmp_prefered_lft = min_t(__u32,
 				 ifp->prefered_lft,
-				 idev->cnf.temp_prefered_lft -
+				 idev->cnf.temp_prefered_lft + age -
 				 idev->cnf.max_desync_factor);
 	tmp_plen = ifp->prefix_len;
 	max_addresses = idev->cnf.max_addresses;

--
To unsubscribe from this list: send the line "unsubscribe netdev" in
the body of a message to majordomo@vger.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
diff mbox

Patch

diff --git a/net/ipv6/addrconf.c b/net/ipv6/addrconf.c
index cfee6ae..9c74454 100644
--- a/net/ipv6/addrconf.c
+++ b/net/ipv6/addrconf.c
@@ -836,7 +836,7 @@  static int ipv6_create_tempaddr(struct inet6_ifaddr *ifp, 
struct inet6_ifaddr *i
 {
 	struct inet6_dev *idev = ifp->idev;
 	struct in6_addr addr, *tmpaddr;
-	unsigned long tmp_prefered_lft, tmp_valid_lft, tmp_cstamp, tmp_tstamp;
+	unsigned long tmp_prefered_lft, tmp_valid_lft, tmp_cstamp, tmp_tstamp, age;
 	unsigned long regen_advance;
 	int tmp_plen;